A memo from department leadership offers safety tips after public outcries over immigration policy.

Officials at the Homeland Security Department warned employees Saturday of a recent increase in threats in the aftermath of the Trump administration’s “zero tolerance” immigration policy.

In a memo to employees over the weekend, acting Deputy Secretary of Homeland Security Claire Grady said there has been an increase in the number of threats made against department employees following the recently implemented policy to prosecute every person who crosses the border illegally, a decision that led to the separation of thousands of children from their parents.

“In recent days, DHS has determined there may be a heightened threat against DHS employees in response to U.S. government actions surrounding immigration,” Grady wrote. “This assessment is based on specific and credible threats that have been levied against certain DHS employees and a sharp increase in the overall number of general threats against DHS employees—although the veracity of each threat varies.”

The memo also made reference to the recent publication of a database of personal information of more than 9,000 Immigration and Customs Enforcement employees, including location, educational background and job history, scraped from LinkedIn.

Additionally, activists hastily organized a protest against DHS Secretary Kirstjen Nielsen after discovering that she was dining at a Mexican restaurant in Washington, D.C., last week.

In light of these recent developments, Grady offered a number of steps employees can take to protect themselves in public. She stressed that if an employee ever feels threatened, he or she should call 9-1-1. If local law enforcement is “slow to respond,” employees can also call the Federal Protective Service.

Additionally, DHS recommended that employees remain “alert” while at or near their workplace, and report any suspicious activity to police or security officers. Employees were advised to “maintain situational awareness” while in public, and to avoid wearing agency badges outside of work.

Grady suggested employees always keep doors and windows at home locked. And she said employees should consider boosting their internet security, from using “strong” passwords to making social media accounts private or being careful about what one posts online.

“Understand that anything you share can be disseminated outside of its intended audience,” Grady wrote. “Be sure to only post information that you’re comfortable with anyone viewing.”

Grady recommended employees pass along these tips to close friends and family as well.

“Keep your heads held high and focused on the department’s important missions,” she wrote. “You are making a difference to secure our country. And in the meantime, let’s continue to be security-conscious and look out for each other.”